1. Field of the Invention
The present invention relates to a control knurl for actuating an appliance, in particular for the rotary adjustment of a potentiometer in automotive vehicles.
2. Description of the Art
A knurl of this type is disclosed in the applicant's German patent application No. 38 08 770. Control knurls of this type must permit being manipulated even if the passenger compartment is dark. Therefore, the dial setting of the potentiometer is illuminated from the inside. Such illumination permits not only recognizing the positioning of the control knurl in the dark but also its respective setting. If needed, adjustment changes can be made.
Because the number of operable adjustment elements on the control panel is constantly rising, it is desired to minimize the energy needed for the dial illumination, while sufficient visibility is ensured in addition. Therefore, one requirement is to minimize, to the extent possible, any light loss which the beams of light suffer on their way to the dial indicating instrument.